The present invention relates to mowing machines of the type having a cutting assembly rotatable in a cutting plane and more particularly to a rotary reel-like casing about which a cutting line made of a high polymer synthetic material is directly coiled.
The field of technology to which the present invention is directed is mowing apparatus of a type wherein a rotary assembly is provided with a coiled nonmetallic line, the effective working length of the line being adapted to be lengthened at desired times while it is in a non-working condition, as the working length becomes shortened during use. Nylon monofilament strings which are almost completely incapable of causing any significant injury to persons or animals struck by the flailing cutting string are effective for use as safe, rotary cutting means. These strings are particularly suitable for cutting or trimming along fences, walls and the trunks or stems of trees.
There is illustrated and described in U.S. Pat. Nos. 3,708,967; 3,826,068; and 3,859,776 one or more embodiments of a mowing device having a rotary head member arranged to be rotated by a gasoline-powered engine or electric motor together with one or more spools which is housed in lockable relation to the rotary head member. A length of flexible nonmetallic line is coiled about the spool and its free end extends peripherally from the spool and the head. The free end swings arcuately about upon the actuation of the engine or motor to cut adjacent vegetation in the manner of a flail. The line storage means in the form of spools is locked from rotation but is releasable so that additional line may be payed out as the effective working length of the line becomes shortened during use.
However, the aforementioned device is subject to certain disadvantages due to having the storage means in the form of spools provided separately from the rotary head member. One of the disadvantages is that the rotary head is complicated in order to provide a means for locking and releasing the spool. As a matter of course, means provided on the rotary head must be as simple as possible because of rotating at high speeds. Also, the device inconveniently needs two procedures of winding a cutting line about the spool and storing the line wound about the spool within the rotary head. Another inconvenience is that the full length of the coiled line or a period of time for replacement of the line is relatively short, because the rotary head has its inside space spared both to the line and to the spool.
In accordance with the present invention aiming to eliminate the aforementioned disadvantages, the apparatus includes an output axis rotatably mounted at one end of a supporting means and connected to a prime mover or a transmission driven thereby. A rotary casing is detachably secured to the output axis for rotation therewith in a cutting plane. The casing consists of a reel-like part and a cap-like part. The reel-like part is composed of upper and lower disk portions and an intermediate cylinder portion about which a cutting line made of a high polymer synthetic material is wound. The cap-like part covers therein the cylinder and lower disk portions together with the coiled line. The cap-like part is mounted on the reel-like part for rotation therewith. A fastening portion is detachably mounted on the output axis for elastically fixing the cap-like part to the reel-like part. The line extends outwardly through one of guide ports provided in the hollow cylindrical wall of the cap-like part to form a cutting flail having an effective working length. The line is made of a high polymer synthetic material which is flexible and yielding to the extent that it is substantially incapable of causing damage or injury when impacting against persons or animals.
The apparatus has the reel-like part as well as the cap-like part elastically pressed to the output axis by a coil spring interposed between the bottom of the cap-like part and a washer detachbly mounted on the output axis. Therefore, when the washer is dismounted, the reel-like part as well as the cap-like part may be easily removed from the output axis and then ready for storing or coiling the cutting line. The cap-like part is depressible from the reel-like part at a distance so as to be rotatable with respect to the reel-like part. Accordingly, an additional line may be payed out by rotating the cap-like part relative to the reel-like part as the effective working length becomes shortened during use.
The apparatus of the present invention contains neither spools separated from a rotary casing nor screws to be operated and therefore is simple in construction and easy for use. The rotary casing has a large inside space spared for line-storage so as to contain a long cutting line for its size. In one embodiment of the present invention, the cylinder portion is formed with a slot having an acute apex in which one end of the line is tightly wedged. A guide port in the form of an open circle is inserted in the underside of an open 8-shaped slit formed in the hollow cylindrical wall of the cap-like part, so that the uncoiled end of the line is easily passed through and well located in it.
In summary, it is an object of the present invention to provide an improved mowing apparatus having a rotary casing in the form of a reel on which a cutting string is immediately coiled.
Another object of the present invention is to provide an improved mowing apparatus which is simple in construction, easy in use and long in a period of renewal.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.